Re: [patch] make pit clocksource continuous

[Stas Sergeev <stsp@aknet.ru>]

Hello.

Thomas Gleixner wrote:
> The PIT can only be used as a clock source, when it is in periodic mode,
> but it is never continuous. If we miss one PIT interrupt the time
> keeping is hosed.
OK, thank you and Daniel for the explanations
about the flag, but now to the problem.
Before hrtimer_switch_to_hres() is called,
the check for timekeeping_is_continuous() is
performed in tick_ckeck_oneshot_change(), and
that check fails (by adding a flag I compel it
to succeed). With that check failing,
hrtimer_switch_to_hres() is never called, and
the hrtimers do not work. That's why I posted
that patch, but what would be the right way
of getting the hrtimers to work?
/proc/timer_list lists only the pit timesource.
If I enable lapic then it is also listed, yet
it doesn't help at all.